• Korean Journal of Veterinary Research
• /
• v.15 no.2
• /
• pp.279-285
• /
• 1975

The experiments were conducted to isolate the etiogical agent and to survey the distribution of Nosema disease in honey bees. The results obtained were as follows: 1. The etiological agent of the so-called "crawling disease" in honey bees characterized by the symptoms of crawling, diarrhea, and enteritis etc. was first isolated and identified with Nosema apis (Zander 1909) in Korea. 2. 455 colonies were randomely sampled and surveyed in 4,766 bee colonies out of 56 apiaries and 51 colonies (11.2%) out of 455 bee colonies were infected with N, apis. 3. Infection rates according to the period of honeyflow as follows: Brassica napus (Apr.): 25/130 colonies (18.4%) Rohinia pseudoacacia (May) : 8/55 colonies (14.%) Trifolium repels(Jun.): 15/99 colonies (13.6%) Castanea crenate (Jul.): 3/46 colonies (6.5%) Lespedeza bicolor(Aug.): 0/60 colonies (-) Fagopyrumesculentum(Sept.) & Perilla frutescens(Oct.) 0/65 colonies (-) 4. The typical clinical signs of Nosema disease were appeared on loth day after N. apis was orally administered with the level of $16{\times}10^4$ spores/ml to the healthy adult bees. Spores could be harvested with the level of $121{\sim}236{\times}10^4$ spores/ml on 10th day and $392{\sim}429{\times}10^4$ spores/ml on 15 days after infection. 5. In adult honey bees infected with N. apis artificially the 50% lethal day of life-span was 9 to 10 days and 100% lethal day was 16 to 19 days. However, in the control 50% lethal day was 19 to 23 days and 100% lethal day was 31 to 33 days.

• Journal of Veterinary Clinics
• /
• v.12 no.1
• /
• pp.887-896
• /
• 1995

In order to determine the efficacy of $Bayvarol^{(R)}$ strips(Bayer AG) against the mite Varroa jacobsoni and the safety of $Bayvarol^{(R)}$ strips in honey bees, a series of trials was carried out under field condition in autumn and spring. The results obtained were as follows; 1. The average varroacidal rate of $Bayvarol^{(R)}$ strips was 92.7% in autumn and 93.7% in spring. However the average varroacidal rats of treated control group was 73.8 % in autumn and 75.1 % in spring, and that of untreated control group was 12.1 % in autumn and 16.1 % in spring. 3. The average number of dead bees in $Bayvarol^{(R)}$ group was 13.0 in recommended dosage(RD), 12.3 in 2 times of RD and 14.0 in 4 times of 70 in autumn, and 19.7 in RD,17.0 in 2 times of RD and 19.0 in 4 times of RD in spring. However the average number of dead bees in treated control groups was 38.3 in RD, 62.7 in 2 times of RD and 60.3 in 4 times of RD in autumn and 18.0 in RD, 43.3 in 2 times of RD and 102 in 4 times of RD in spring and that of untreated control of group was 12.7 in autumn and 19.3 in spring. 3. The varroacidal effects and the number of dead bees of all groups were higher in spring than in autumn. 4. It was revealed that $Bayvarol^{(R)}$ were highly saft and effective varroacides for honey bees.

• Korean Journal of Environment and Ecology
• /
• v.33 no.6
• /
• pp.654-663
• /
• 2019

Pollinators, which are important organisms in pollination ecology, have been highly valued for their economic contributions to crop production in the agricultural and biotechnology industries. As the production of over 70% of farm products, such as fruits, are mediated by pollinators, bees are important and useful insects to humans. However, pollinators are now seriously threatened with their numbers decreasing annually and their biodiversity being negatively affected by ongoing climate change, misuse of land, change of geographical features, and use of pesticides to increase agricultural production. Thus, surveys and analyses of the emergence and distribution of wild bees are important for conservation and management practices designed to help them continue to play their ecological and agricultural roles despite negative pressures, such as climate and topography changes. We surveyed pollinators, especially wild bees, at 51 research sites in South Korea every two to four weeks for two years from 2017 to 2018 using ez-Malaise traps and analyzed the temporal and spatial distribution of wild bees. The bees showed a normal temporal distribution that peaked between July and August. The bees' working period lasted until November. The spatial distribution of wild bees showed a significant correlation with latitude, and different bees were identified depending on the local habitat. No significant correlation was found for longitudinal distribution with regression analysis (p > 0.05), but this study identified locally specific wild bees. Although we could not predict significant distribution according to longitude, Further studies should be able to analyze the difference in the distribution of wild bees according to the climate, topography, and land-use patterns by humans. The results of this study provide basic information on pollinator distribution, which can be useful in agriculture and for the conservation and management of biodiversity in South Korean pollination ecology.

• Current Research on Agriculture and Life Sciences
• /
• v.32 no.2
• /
• pp.63-66
• /
• 2014

The effects of a newly developed flower thinning formulation (FTF) on the vitality of the honey bee Apis mellifera were examined by measuring the activities of various digestive enzymes in adult worker bees. First, direct spraying of the FTF solution did not cause any behavioral changes or lethal effects for the honey bees based on 24 h observation. Second, oral ingestion of a sugar solution containing the FTF did not produce any significant change in the activities of amylase, proteinases, lipase, or acetylcholine esterase (AChE) in the worker bees 6 h or 24 h after treatment. Meanwhile, a commercial formulation containing sulfur compounds showed slightly reduced activities for several digestive enzymes and AChE, although no behavioral disturbance. Thus, the results of the present study suggest that the FTF is not toxic for honey bees, in terms of contact and ingestion. Therefore, this newly developed FTF can be used for flower thinning without any detrimental effects on pollinating insects.

• Mycobiology
• /
• v.45 no.3
• /
• pp.204-208
• /
• 2017

Nosema ceranae is an obligate intracellular fungal parasite that causes mortality in honey bees and enhances the susceptibility of honey bees to other pathogens. Efficient purification of Nosema spores from the midgut of infected honey bees is very important because Nosema is non-culturable and only seasonably available. To achieve a higher yield of spores from honey bees, in this study, we considered that the initial release of spores from the midgut tissues was the most critical step. The use of 2 mm beads along with enzymatic treatment with collagenase and trypsin enhanced the homogenization of tissues and the yield of released spores by approximately 2.95 times compared with the use of common 3 mm beads alone. The optimal time for the enzyme treatment was determined to be 1 hr as measured by the yield and viability of the spores. A one-step filtration using a filter paper with an $8-11{\mu}m$ pore size was sufficient for removing cell debris. This method may be useful to purify not only N. ceranae spores but also other Nosema spp. spores.

• Earthquakes and Structures
• /
• v.16 no.2
• /
• pp.165-175
• /
• 2019

Incremental dynamic analysis (IDA), as an accurate method to evaluate the parameters of structural performance levels, requires many non-linear time history analyses, using a set of ground motion records which are scaled to different intensity levels. Therefore, this method is very computationally demanding. In this study, a new method is presented to estimate the summarized (16%, 50%, and 84% fractiles) IDA curves of a first-mode dominated structure using discrete wavelet transform and bees optimization algorithm. This method reduces the number of required ground motion records for the prediction of the summarized IDA curves. At first, a subset of first list ground motion records is decomposed by means of discrete wavelet transform which have a low dispersion estimating the summarized IDA curves of equivalent SDOF system of the main structure. Then, the bees algorithm optimizes a series of factors for each level of detail coefficients in discrete wavelet transform. The applied factors change the frequency content of original ground motion records which the generated ground motions records can be utilized to reliably estimate the summarized IDA curves of the main structure. At the end, to evaluate the efficiency of the proposed method, the seismic behavior of a typical 3-story special steel moment frame, subjected to a set of twenty ground motion records is compared with this method.

• The Korean Journal of Food & Health Convergence
• /
• v.5 no.1
• /
• pp.33-38
• /
• 2019

The purpose of previous study centered around introducing minerals into bee colonies was to observe the Varrosa destructor mites-repelling effect of minerals ("Pszczelarstwo" 6/2016). The results of research published so far confirmed the purpose of using minerals in the fight against Varrosa infestation. This publication presents partial results of the next stage of research. Using foundation enriched with studied minerals in right proportions leads to diminishing the number of Varroa destructor parasites in bee colonies. It may also contribute to increase in the amount of honey obtained from bees. Foundations with minerals were in most cases correctly filled with larvae, and the new generation of bees didn't show any morphometric or physical-motor aberrations. The effect of minerals in the foundation weakens with time, which requires adequate reaction from the beekeeper. The study showed no negative effect of mineral suspensions added directly to royal jelly of larvae in the swarm cells and worker cells on the development of bees. Additional research was carried out in August and September and led to surprising observations, which are still too early to report. It obliges us to carry out further, extended subject research on a large number of bee colonies in 2017.

• Journal of Ecology and Environment
• /
• v.46 no.1
• /
• pp.62-75
• /
• 2022

Background: Pollinators help plants to reproduce and support economically valuable food for humans and entire ecosystems. However, declines of pollinators along with population growth and increasing agricultural activities hamper this mutual interaction. Nectar and pollen are the major reward for pollinators and flower morphology and volatiles mediate the specialized plant-pollinator interactions. Limited information is available on the volatile profiles attractive to honey bees and bumblebees. In this study we analyzed the volatile organic compounds of the flowers of 9 different plant species that are predominantly visited by honey bees and bumblebees. The chemical compositions of the volatiles were determined using a head space gas chromatography-mass spectrometry (GC-MS) method, designed to understand the plant-pollinator chemical interaction. Results: Results showed the monoterpene 1,3,6-octatriene, 3,7-dimethyl-, (E) (E-𝞫-ocimene) was the dominating compound in most flowers analyzed, e.g., in proportion of 60.3% in Lonicera japonica, 48.8% in Diospyros lotus, 38.4% Amorpha fruticosa and 23.7% in Robinia pseudoacacia. Ailanthus altissima exhibited other monoterpenes such as 3,7-dimethyl-1,6-octadien-3-ol (𝞫-linalool) (39.1%) and (5E)-3,5-dimethylocta-1,5,7-trien-3-ol (hotrienol) (32.1%) as predominant compounds. Nitrogen containing volatile organic compounds (VOCs) were occurring principally in Corydalis speciosa; 1H-pyrrole, 2,3-dimethyl- (50.0%) and pyrimidine, 2-methyl- (40.2%), and in Diospyros kaki; 1-triazene, 3,3-dimethyl-1-phenyl (40.5%). Ligustrum obtusifolium flower scent contains isopropoxycarbamic acid, ethyl ester (21.1%) and n-octane (13.4%) as major compounds. In Castanea crenata the preeminent compound is 1-phenylethanone (acetophenone) (46.7%). Conclusions: Olfactory cues are important for pollinators to locate their floral resources. Based on our results we conclude monoterpenes might be used as major chemical mediators attractive to both honey bees and bumblebees to their host flowers. However, the mode of action of these chemicals and possible synergistic effects for olfaction need further investigation.

• Journal of Korean Society of Disaster and Security
• /
• v.16 no.4
• /
• pp.85-99
• /
• 2023

By the social advancement, radiological disaster prevention planning is getting important considering complex disasters as in the Fukushima radiological disaster occurred by a chain of natural disasters. However, it has yet to be suggested the specific prevention plans for the complex disasters in the field of national radiological disaster prevention. This study aims to analyze the types of complex disasters in order to select the ones that are relatively more likely to occur in the domestic environment. It is also to analyze the impact on the radiological disaster prevention by searching damage spread of the classified natural disasters. We provides the necessary criterial for establishing disaster prevention plans through the scenarios for radiological emergency responses based on complex disasters. it is thought that these criteria can help prepare for the worst case scenario and implement effective resident protection.

• Korean Journal of Veterinary Research
• /
• v.16 no.1
• /
• pp.11-25
• /
• 1976

Studies on pathogenicities and developmental stages of Nosema apis (Zander, 1909) were carried out through artificial infection to Nosema free honey bees with various levels of spores isolated from local honey bee colony. The results obtained were summarized as follows: 1. The clinical symptoms were observed as dysentery, enteritis of mid-gut (enlargement and decoloration), crawling posture and shortening of the longevity of worker bees in the rearing honey bee colony inoculated with the spores. 2. Number of spores harvested from laboratory rearing honey bees were progresively increased to 4 weeks after inoculation. The regression equations and coefficients of correlations to various spore levels were as follows in each treatment colony. Colony 1. ($$1,000{\times}10^4spores/ml$$) $$y_{c1}=471{\times}10^{4}x+454{\times}10^4(r=0.65^*$$) Colony 2. ($$500{\times}10^4spores/ml$$) $$y_{c2}=340{\times}10^{4}x+207.8{\times}10^4(r=0.99^{**}$$) Colony 3. ($$100{\times}10^4spores/ml$$) $$y_{c3}=150{\times}10^{4}x+84.2{\times}10^4(r=0.99^{**}$$) Colony 4. ($$10{\times}10^4spores/ml$$) $$y_{c4}=13.8{\times}10^{4}x+13{\times}10^4(r=0.98^{**}$$) 3. Average longevity of worker bees artificially infected with Nosema apis was shortened as 21.7~43.8% compare to the control. (p<.05, p<.01) 4. The spores which were isolated from honey bee colony infected with Nosema disease were ovoid or spherical form, and measured, as a rule, from $4.7{\mu}m$ to $6.1{\mu}m$ (mean $5.3{\mu}m$) in length and from $2.4{\mu}m$ to $3.2{\mu}m$ (mean $2.9{\mu}m$) in width. 5. In the mid-gut of honey bees, the spore was progresively germinated and became trophozoite stage. The trophozoites were grown to meronts and their binary fission were begun. The divided two sporoblasts were developed to the spores which had elastic membrane. The new spores were shed in excreta of honey bees 10~15 day after inoculation at $25{\pm}2$ centigrade. 6. The ultrastructure of spore membrane consisted of three layers, such as, outer, middle and inner layer. The sporoplasm consisting lamellar structure occupied only anterior part of the spore and was often extended to posterior direction where definite vacuoles and a polar filament was able to detect.